Thesis (Ph. D.)--Duke University, 2008. / Includes bibliographical references.

Thesis (M.S.)--Brigham Young University. Dept. of Integrative Biology, 2005. / Includes bibliographical references.

Thesis (Ph. D.)--University of Canterbury, 2010. / Typescript (photocopy). Includes bibliographical references (p. 231-255). Also available via the World Wide Web.

Relationships between two taxonomic kingdoms; plants and herbivorous insects, are hypothesized to be a major zone of interaction for generating current day biodiversity; and coevolutionary processes between these intricately linked organisms are hypothesized to maintain diversity in plant secondary chemistry. These metabolites play a key role in plant defence against herbivory and a high degree of intraspecific variation is observed at multiple ecological scales. However, the nature of selection maintaining variation in plant defence profiles is still a major question in evolutionary biology and ecology, and progress towards a deeper understanding is hampered by a lack of studies that take into account ecological context and the multivariate nature of plant defence phenotypes. In this thesis, I employ sophisticated chemical analysis techniques to identify a suite of glucosinolate secondary chemicals, representing different biosynthetic pathways, in the wild cabbage, Brassica oleracea, in natural populations in the UK. I used model-based cluster analysis to explore patterns of association between individual glucosinolates, predicting that as simultaneous resource allocation to multiple defences is likely to be constrained; negative associations between defensive traits should be observed. However, results revealed positive associations between glucosinolates. Therefore co-expression of multiple defences may not be costly for this species. Using this information in conjunction with herbivore surveys and experiments, I show that this mixture has the potential to shape patterns of herbivore abundance and host plant utilization: species-specific responses to variation in glucosinolate phenotypes are discovered at various ecological scales. Thus there is the potential for differential selection on plant chemotypes though species-specific attractions and aversions. By conducting fine scale experiments with herbivore species, I also found that glucosinolate variation has an impact on the counter-adaptations that some brassica specialists have evolved: in order to optimally defend against their own natural enemies, Brevicoryne brassicae aphids sequestering glucosinolates from their host plants must do so selectively, and must choose plants whose chemical profile best matches this behaviour. These findings show that glucosinolate profiles may be under natural selection by herbivores in wild populations, and that reciprocal evolution between these plants and their specialists may continue to promote diversity in secondary metabolites. Together these results highlight the complexity inherent in plant-insect interactions, the importance of field studies and generate a wealth of testable hypotheses for future work.

Synthetic cannabinoids were first created in a pharmaceutical setting where scientists were studying marijuana. Researchers were trying to develop medically beneficial marijuana analogs. The compounds, however, were found to give physiological effects that were more potent than marijuana. Presently, synthetic cannabinoids have become a psychoactive drug of abuse, sold in head shops and over the Internet. New compounds are constantly being synthesized, which makes analysis of the drugs difficult. Solid phase extraction (SPE) is a well-studied method used in toxicological analysis to extract drugs and their metabolites from biological fluids. This sample preparation method is necessary to isolate the desired components of a sample for analysis by gas chromatography and mass spectrometry (GC/MS). This study sought to compare four brands of commercially available SPE cartridges using a procedure from United Chemical Technologies (UCT) for the simultaneous extraction of the three synthetic cannabinoid metabolites, JWH-018 N-(4-hydroxypentyl), JWH-122 N-(5-hydroxypentyl), and JWH-250 N-(5-hydroxypentyl), from urine. The cartridges from UCT, Thermo Scientific, Agilent Technologies, and SiliCycle were evaluated to determine how they performed throughout the SPE procedure. A recovery efficiency study was conducted to measure the amount of extracted metabolites from the urine. The responses of the quantification ion of the metabolites from an extracted urine sample were compared to a neat sample and the percent recovery was calculated. A within-run precision study was also utilized to measure the reproducibility of the cartridges, which was determined by the coefficient of variation (CV) of the different brands. The outcome of this research led to a development of a GC/MS method for detection of the three metabolites, creation of calibration curves for quantification, use of SPE for the extraction of the metabolites from urine, and the quantification of the extracted compounds to determine the efficacy and consistency of four brands of SPE cartridges. Method optimization was able to minimize the interday variations seen in the results of aliquots of the same samples. Optimal parameters include initial validation of the GC/MS method, a clean liner for the analysis of synthetic cannabinoid metabolites, using a GC column with a high temperature limit, and derivatization of the extracts before injection into the GC. While this study shows it is possible to use GC/MS for the analysis of these metabolites, LC/MS does not have the same restrictions because a liner, temperature elution, and derivatization of the analytes are not utilized. It was determined from the results of these studies that SiliCycle had the most reproducible and efficient cartridges. SiliCycle cartridges had a consistent and fast flow rate with a percent recovery efficiency within ±20% of the actual value. The results from SiliCycle were followed by cartridges from UCT, Thermo Scientific, and Agilent brands, respectively.

Cyanobacterial secondary metabolites are a rich source of bioactive compounds with potential utilization in pharmacology. The aim of this study was to evaluate the effect of the novel compound nostatin A isolated from the cyanobacterium Desmonostoc muscorum. Project was focused on the extraction, purification and characterization of the cytostatic effect caused by this novel compound and its naturally occurred structural analogues. The cytostatic activity of nostatin A and its analogs was evaluated in HeLa cell line. Experiments based on microscopy, flow cytometry and HPLC-HRMS techniques were performed in order to clarify the cytostatic effect of nostatin A in HeLa cells and its mechanism of the action.

Submitted by Mariana Gabriela Fonseca (marigfonseca@yahoo.com.br) on 2018-09-17T13:01:19Z No. of bitstreams: 1 Fonseca, MG_Dissertacao Mestrado Corrigida-merged (1).pdf: 5024373 bytes, checksum: 7883e82b0d1dc259f5f8c6567a8c452b (MD5) / Approved for entry into archive by Adriana Aparecida Puerta null (dripuerta@rc.unesp.br) on 2018-09-17T14:03:13Z (GMT) No. of bitstreams: 1 fonseca_mg_me_rcla.pdf: 5024373 bytes, checksum: 7883e82b0d1dc259f5f8c6567a8c452b (MD5) / Made available in DSpace on 2018-09-17T14:03:13Z (GMT). No. of bitstreams: 1 fonseca_mg_me_rcla.pdf: 5024373 bytes, checksum: 7883e82b0d1dc259f5f8c6567a8c452b (MD5) Previous issue date: 2018-07-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Ainda que consideráveis avanços tecnológicos no setor agrícola tenham proporcionado melhorias no bem-estar humano, milhares de pessoas ainda enfrentam miséria e fome ao redor do mundo. O progresso alcançado no último século, com a Revolução Verde, apesar de ter impulsionado a produção global de alimentos, também trouxe consequências catastróficas para o ambiente natural. Além disso, a população mundial continua a crescer exponencialmente, em especial em regiões emergentes como nos continentes africano e asiático. Todos esses fatores, somados aos inúmeros limitantes das produções agrícolas, representam uma grande ameaça à segurança alimentar do planeta, além de trazer prejuízos econômicos exorbitantes. Dentre os limitantes agrícolas, as fitopatologias causadas por bactérias do gênero Xanthomonas respondem por perdas de produção que podem chegar a 100%, quando em situação epidêmica. As produções de tomate, pimentão e mandioca podem ser reduzidas gravemente quando acometidas por Xanthomonas euvesicatoria, causadora da mancha bacteriana em pimentão e tomateiros, e Xanthomonas axonopodis pv. manihotis, causadora da bacteriose da mandioca. O combate atual para estas doenças baseia-se no uso de compostos cúpricos, notadamente danosos à saúde humana e ambiental, mas há casos, como o da bacteriose da mandioca, em que não há controle químico eficaz, sendo medidas de controle e manejo a única possibilidade de amenizar o problema. Como alternativa, estudos vem apontado a possibilidade de uso de metabólitos secundários de microrganismos, incluindo fungos da Antártica, no combate às Xanthomonas ssp. A presente pesquisa avaliou o potencial bactericida de extratos produzidos por 156 fungos isolados de diversas amostras de solo e sedimentos marinhos antárticos contra X. euvesicatoria e X. ax. pv. manihotis. Vinte e sete extratos foram bioativos para pelo menos uma das espécies de Xanthomonas testadas. Os extratos bioativos foram produzidos por 23 diferentes fungos, sendo que 9 foram isolados de amostras de sedimentos marinhos, 5 de solo abaixo de madeira podre, 6 de solo com biofilme e 3 isolados de solo abaixo de barra de ferro. O gênero de fungos Pseudogymnoascus, bastante comum na Antártica, foi predominante dentre os isolados foram produtores de compostos bioativos contra as espécies testadas. / Yet considerable technological advances in the agricultural sector have provided improvements in human well-being, thousands of people still face misery and hunger around the world. The progress achieved in the last century within the Green Revolution, despite having boosted global food production, has also brought catastrophic consequences to the natural environment. In addition, the world population continues to grow exponentially, especially in emerging regions such as the African and Asian continents. All these factors, coupled with the numerous constraints of agricultural production, pose a great threat to the planet's food security, as well as exorbitant economic losses. Among the agricultural limitations, phytopathologies caused by bacteria of the genus Xanthomonas respond by losses of production that can reach 100%, when in an epidemic situation. The tomato, pepper and cassava productions can be severely reduced when affected by Xanthomonas euvesicatoria, which causes bacterial spot in pepper and tomatoes, and Xanthomonas axonopodis pv. manihotis, which causes cassava bacterial blight. The current fight for these diseases is based on the use of copper compounds, notably harmful to human and environmental health, but there are cases, such as cassava bacterial blight, in which there is no effective chemical control, and management measures are the only possibility of mitigating the problem. As an alternative, studies have indicated the possibility of using secondary metabolites of microorganisms, including Antarctic fungi, in the control of Xanthomonas ssp. The present study evaluated the bactericidal potential of extracts produced by 156 fungi isolated from several soil samples and marine sediments against X. euvesicatoria and X. ax. pv. manihotis. Twenty-seven extracts were bioactive for at least one of the Xanthomonas species tested. Bioactive extracts were produced by 23 different fungi, of which 9 were isolated from marine sediment samples, 5 from soil under rotten wood, 6 from soil with biofilm and 3 soil isolates below iron bar. The genus of fungi Pseudogymnoascus, very common in Antarctica, was predominant among the isolates were producers of bioactive compounds against the species tested.

Made available in DSpace on 2014-06-11T19:23:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-06-13Bitstream added on 2014-06-13T20:29:50Z : No. of bitstreams: 1 baeta_ds_me_araiq_parcial.pdf: 109419 bytes, checksum: 134e077009d1de2ee116ccdf92f939fb (MD5) Bitstreams deleted on 2015-06-25T13:01:03Z: baeta_ds_me_araiq_parcial.pdf,. Added 1 bitstream(s) on 2015-06-25T13:03:23Z : No. of bitstreams: 1 000721762_20151231.pdf: 96024 bytes, checksum: 0424092e2572769f235bbe98565fed9c (MD5) Bitstreams deleted on 2016-01-04T10:26:24Z: 000721762_20151231.pdf,. Added 1 bitstream(s) on 2016-01-04T10:28:16Z : No. of bitstreams: 1 000721762.pdf: 814938 bytes, checksum: 7409e58168c23f840f8506080e75c02b (MD5) / O Cerrado ocupa aproximadamente 22% do território nacional e compreende uma grande variabilidade tanto de clima e de solo, quanto de fauna e de flora. Dentre suas espécies típicas, o pequi (Caryocar brasiliense Camb.) é conhecido, consumido e cultivado principalmente por populações nativas desse bioma, sendo considerado como “rei do Cerrado” devido ao seu valor alimentício, nutricional e socioeconômico. Possui índices altos de carboidratos, proteínas, vitaminas e sais minerais, além de um sabor peculiar. Tem na culinária sua principal utilização. É um fruto sazonal, cuja carência na entressafra é suprida utilizando-se a polpa, parte do fruto comestível, em conservas, em pastas e congelada. Dessa forma, esse trabalho teve como proposta avaliações físico-químicas e bioquímicas do pequi em duas diferentes formas de armazenamento: in natura e em conserva. Dados obtidos mostraram o pH da polpa in natura de 5,4, sendo considerado pouco ácido, e o em conserva de 3,8, considerado muito ácido, evitando assim a deterioração e o crescimento de bactérias, fungos e leveduras. Extratos aquosos e etanólicos das amostras apresentaram conteúdo proteico de 0,19 g.100g-1 à 11,88 g.100g-1, sendo a extração aquosa mais eficiente e os valores para a polpa in natura estão de acordo com a literatura. Em relação ao teor de compostos fenólicos, da polpa in natura liofilizada, foi superior aos encontrados em várias frutas brasileiras e, neste caso, a extração etanólica foi a mais eficiente. Os valores de vitamina C da polpa de pequi in natura (76,53 mg.100gpolpa-1) e em conserva (99,17 mg.100gpolpa-1) indicaram que este fruto é fonte média desta vitamina, sendo que o teor no fruto in natura foi superior ao de algumas frutas cítricas e tropicais, como do limão e... / The Cerrado occupies approximately 22% of the national territory and it comprises a large variability both in climate and soil, as of fauna and flora. Among its typical species, the pequi (Caryocar brasiliense Camb.) is known, consumed and grown mainly by native populations of this biome, being considered as King of the Cerrado due to its nutritional and socioeconomic values. It has high levels of carbohydrates, proteins, vitamins and minerals, plus a peculiar flavor. It has its main use in culinary. It is a seasonal fruit, and in the offseason the demand is supplied with the pulp, the part of the fruit that is edible, in preserves, paste and frozen. Thus, this work had the purpose to perform physicochemical and biochemical analysis of pequi in two different storage forms: fresh and preserved. Data obtained showed pH of fresh pulp of 5.4, being considered slightly acidic, and pickled of 3.8, considered too acidic, thus avoiding deterioration and the growth of bacteria, fungi and yeasts. Water and ethanol extracts of samples presented protein content of 0.19 g.100g-1 to 11.88 g.100g-1, with an aqueous extraction more efficient and the values for the fresh pulp are consistent with the literature. In relation the phenolic content, of fresh pulp lyophilized, they are superior to those found in several Brazilian fruits and, in this case, the ethanolic extract was the most effective. The values of vitamin C from fresh pulp pequi (76.53 mg.100gpulp-1) and preserved (99.17 mg.100gpulp-1) indicated that this fruit is an average source of this vitamin, and the content in fresh fruit was higher than in some tropical and citrus fruits such as lemon and guava. The antioxidant activity, of lyophilized samples, can be related to the phenolic content and the content of vitamin C, both determined in this... (Complete abstract click electronic access below)

Orientador: Olga Maria Mascarenhas de Faria Oliveira / Coorientador: Marcos Barros de Souza / Banca: Antonio Baldo Geraldo Martins / Banca: Flávio Luís Schmidt / Resumo: O Cerrado ocupa aproximadamente 22% do território nacional e compreende uma grande variabilidade tanto de clima e de solo, quanto de fauna e de flora. Dentre suas espécies típicas, o pequi (Caryocar brasiliense Camb.) é conhecido, consumido e cultivado principalmente por populações nativas desse bioma, sendo considerado como "rei do Cerrado" devido ao seu valor alimentício, nutricional e socioeconômico. Possui índices altos de carboidratos, proteínas, vitaminas e sais minerais, além de um sabor peculiar. Tem na culinária sua principal utilização. É um fruto sazonal, cuja carência na entressafra é suprida utilizando-se a polpa, parte do fruto comestível, em conservas, em pastas e congelada. Dessa forma, esse trabalho teve como proposta avaliações físico-químicas e bioquímicas do pequi em duas diferentes formas de armazenamento: in natura e em conserva. Dados obtidos mostraram o pH da polpa in natura de 5,4, sendo considerado pouco ácido, e o em conserva de 3,8, considerado muito ácido, evitando assim a deterioração e o crescimento de bactérias, fungos e leveduras. Extratos aquosos e etanólicos das amostras apresentaram conteúdo proteico de 0,19 g.100g-1 à 11,88 g.100g-1, sendo a extração aquosa mais eficiente e os valores para a polpa in natura estão de acordo com a literatura. Em relação ao teor de compostos fenólicos, da polpa in natura liofilizada, foi superior aos encontrados em várias frutas brasileiras e, neste caso, a extração etanólica foi a mais eficiente. Os valores de vitamina C da polpa de pequi in natura (76,53 mg.100gpolpa-1) e em conserva (99,17 mg.100gpolpa-1) indicaram que este fruto é fonte média desta vitamina, sendo que o teor no fruto in natura foi superior ao de algumas frutas cítricas e tropicais, como do limão e... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Cerrado occupies approximately 22% of the national territory and it comprises a large variability both in climate and soil, as of fauna and flora. Among its typical species, the pequi (Caryocar brasiliense Camb.) is known, consumed and grown mainly by native populations of this biome, being considered as "King of the Cerrado" due to its nutritional and socioeconomic values. It has high levels of carbohydrates, proteins, vitamins and minerals, plus a peculiar flavor. It has its main use in culinary. It is a seasonal fruit, and in the offseason the demand is supplied with the pulp, the part of the fruit that is edible, in preserves, paste and frozen. Thus, this work had the purpose to perform physicochemical and biochemical analysis of pequi in two different storage forms: fresh and preserved. Data obtained showed pH of fresh pulp of 5.4, being considered slightly acidic, and pickled of 3.8, considered too acidic, thus avoiding deterioration and the growth of bacteria, fungi and yeasts. Water and ethanol extracts of samples presented protein content of 0.19 g.100g-1 to 11.88 g.100g-1, with an aqueous extraction more efficient and the values for the fresh pulp are consistent with the literature. In relation the phenolic content, of fresh pulp lyophilized, they are superior to those found in several Brazilian fruits and, in this case, the ethanolic extract was the most effective. The values of vitamin C from fresh pulp pequi (76.53 mg.100gpulp-1) and preserved (99.17 mg.100gpulp-1) indicated that this fruit is an average source of this vitamin, and the content in fresh fruit was higher than in some tropical and citrus fruits such as lemon and guava. The antioxidant activity, of lyophilized samples, can be related to the phenolic content and the content of vitamin C, both determined in this... (Complete abstract click electronic access below) / Mestre

Orientador: Ian Castro-Gamboa / Banca: Fabíola Manhas Verbi Pereira / Banca: Flávia Talarico Saia / Resumo: Este trabalho de mestrado tem, como foco principal, analisar o comportamento do fungo Xylaria sp. perante variações físico - químicas, através da abordagem OSMAC (One Strain, Many Compounds). Para realizar tais induções e explorar a variabilidade da rede metabólica deste micro - organismo, um planejamento fatorial foi desenhado visando induzir a variabilidade (ou a potencialização) de metabólitos. Diante de respaldos quim iométricos, induções planejadas foram impostas ao micro - organismo e observou - se variações no perfil químico nos extratos brutos. Somado a isso, técnicas de desreplicação foram usadas a fim de estudar quimicamente as matrizes complexas produzidas por este fungo visando a produção de metabólitos de alto valor agregado e determinou - se condições específicas para produção de moléculas de citocalasina D e de griseofulvina. / Abstract: This work has as its main focus, analyze the behavior of the fungus Xylaria sp. before physicochemical variations via the OSMAC approach (One Strain, Compounds Many). To achieve such induction and exploit the variability of the metabolic network of this micro - organism, a factorial design was designed to induce variability (or potentiating) metabolites. Before chemometric backrests, planned inductions were imposed on the micro - organism and it was observed variations in the chemical profile in crude extracts. Added to this, dereplication techniques were used to study the che mically complex matrices produced by this fungus aimed at producing high added value and metabolites was determined specific conditions for the production of molecules cytochalasin D and griseofulvin. / Mestre